Energex says it has now reconnected electricity to around 80,000 customers.

But more than 77,000 customers are still without power in south-east Queensland, with the majority in Brisbane's south and west, as well as around Ipswich.

Spokesman Danny Donald says floodwaters are hampering efforts to restore power in many areas.

"As we've seen all along you don't want to take any vehicles through floodwaters, you're asking for trouble," he said.

"So we're in the boat with everyone else in that we've got a few access issues.

"I guess on the bright side we have actually reconnected around 80,000 customers since last night."

Many homes in the riverside suburbs of Chelmer, Graceville and Indooroopilly are still submerged, with water lapping at the awnings.

Their owners are being ferried around on boats to survey the damage and start planning the clean-up.

Devastating scenes

Local resident Alan Bates says the damage is devastating.

"It's been heart breaking. We've been operating in this lower area of Chelmer and Graceville," he said.

"We went out at 6:30 this morning to take a friend out to their place. Most of the low-set houses have been completely submerged and with high-storey houses the water has quite often made it a foot or two into the upper levels."

Some residents in the south-western suburb of Fig Tree Pocket say they were not warned their homes were at risk.

The main road into the suburb is cut and many homes are flooded up to the roof, with residents still evacuating.

One local resident said on Tuesday morning that they were told only two homes in the suburb would be flooded.

"We left thinking that the road would be cut off then discovered when the road was cut off that we could lose our homes," the resident said.

"We didn't pack a single valuable. All we had were clothes and essentials and I guess we feel a little bit let down that they could have predicted it a bit more accurately at the beginning.

"But they say floodwater is about 1.5 metres higher than it was in 1974."

She says the warnings gave no indications levels would get so high.

"Most of us thought that we were being very conservative because our neighbours were their putting furniture up on high points and things, and of course they then ended up with water up over their roofs," she said.

"There was a lot of effort that went in on the early stages that could have been better spent if we'd had more accurate information on Tuesday morning."

Kilcoy, north-west of Brisbane, remains isolated and police are urging residents to conserve food, water and fuel.

The town had a flash-flood on Tuesday and roads to the east and west are still cut.

Authorities say they are working to restock the local supermarket.

Emergency housing

Queensland Premier Anna Bligh says demountables are being brought in from across Australia to house residents displaced by the floods.

Around 3,000 people are being accommodated in evacuation centres throughout south-east Queensland and many others are staying with family and friends.

It is likely to be months before residents can return home and Ms Bligh say interim accommodation is needed.

She has not put a number on how many demountables will be needed but says they will be set up in cities and towns through the south-east.

"This is not a long-term solution, this is short-term between the evacuation centre and being back in their own homes," she said.

Ms Bligh has also urged people to stop taking donations to evacuation centres as a backlog of goods and clothing is creating problems for staff.

Dam levels dropping

SEQ Water says the storage levels of Wivenhoe and Somerset dams are gradually falling.

A million megalitres of water a day had been flowing into the dams during the peak of the weather event.

Spokesman Dan Spiller says the water release rate has been reduced significantly.

"At the moment we're releasing about 2,500 cubic metres per second from the dams. What that's meant is that Wivenhoe Dam has come down to a bit below 190 per cent [full] and Somerset Dam's come down to about 175 per cent," he said.

Now that water levels upstream of the city are falling, water grid manager Barry Dennien says dam levels need to be lowered to make room for inflows.

"What we're intending to do is let the water out of the storage compartment now over seven days and as we let it out we are going to be very, very careful that we don't create another flood that follows the one we have just had," he said.

Brisbane businesses are counting the cost of the floods that have engulfed the city.

Gary Hume's car repair business at Albion, on the northside, has become an indoor pool. Staff at the workshop moved stock to any perch they could find before the floodwaters hit.

Mr Hume says if the water had come just centimetres higher critical equipment would have been destroyed.

"It saved the control box for my spray booth and that would have put me out of work for months," he said.

"I started in 1976 and it's sort of like part of the family. You get a little bit attached to the business of course and to see it go down like this is not fun."

Mr Hume says there was nothing he could do to stop it and like many other traders he has been forced to watch and prepare for the clean-up.

Meanwhile, the Queen has made a personal donation to the Queensland Premier's flood relief fund.

The amount she donated has not been disclosed.

British prime minister David Cameron phoned Prime Minister Julia Gillard to offer any assistance and pass on his admiration for the resilience of those affected.

Opposition leader Ed Milliband added his support for the flood victims and there are reports many UK residents and companies have also been making donations to the flood appeal.

Volunteers on the way

Volunteers from Western Australia will today start helping with the search and rescue effort.

Four specialists have flown to Brisbane and their role will include helping to rescue trapped people, and recover bodies.

WA Emergency Services Minister Rob Johnston says the State Government is on stand-by to help with the "grim job" and will respond to any further requests for assistance.

"Initially they will obviously be trying to find people that are trapped but we are hoping that they won't find another task which is finding people who are deceased. But that is all part of their job," he said.

"If we get a request from Queensland to send more people then we will obviously send them as a matter of urgency. We want to do whatever we can to help our Queensland cousins."

Allan Gale from the Fire and Emergency Services Authority says WA has plenty of volunteers that can help if needed.

"There's thousands of volunteers in this state that would be eager to put their hand up to go over there and help," he said.

"Should more requests come, I know we would support those too and FESA would look to the various resources that we've got."